ES2261640T3 - WATERFUL COATINGS AND THICKNESSES THAT CONTAINS A LIGHT FILMOGEN POLYMER. - Google Patents

Abstract

Aqueous thick coating composition with a determined pH containing a polymeric binder and a macromolecular thickener where a) such a thickener contains macromolecules having hydrophilic parts at the chosen pH, and b) such a thickener dispersed in water at a concentration of 2% by weight (with with respect to the combined thickener and water weights) it has a low shear viscosity of at least 0.1 Paus when measured at 18 ° C in a Brookfield viscometer with a No. 3 Spindle that rotates at 12 rpm characterized in that the macromolecules They are cellulose free and because they also contain auto-oxidizable parts, creating a cellulose-free auto-thickener.

Description

Aqueous and thick coating compositions containing a film-forming polymeric binder.

This invention relates to a composition of aqueous and thick coating containing a polymeric binder film forming and a macromolecular thickener. It also refers to a macromolecular thickener for use in the composition and to a polymerizable compound for use in obtaining thickener

Aqueous coating compositions Thickeners are commonly used for coating building surfaces, where surfaces are normally coated, at room temperatures of say 5 to 40 ° C, using for example brushes, rollers, sponges or sprayers such as application tools These compositions are usually called often "architectural" coating compositions and They include paints, lacquers, varnishes, wood stains and adhesives. The thickening of a coating composition facilitates its load in the application tools and their subsequent application on the architectural surfaces.

An aqueous thick coating composition normally contains not only the macromolecular thickener, water and a polymeric binder but also solid non-particulate binders as inorganic and / or organic pigments or opacifiers (for example titanium-rutile dioxide or particles organic polymeric containing hollows) or extenders (for example plaster, dolomite, clays or talcum powder), as well as others optional ingredients as matting agents (for example silica), structure agents (for example titanium chelates or zirconium or laponite or bentonite clays), coalescing solvents (for example, moderately volatile alcohols such as alcohol benzyl or hydrocarbons such as turpentine), antifoaming agents and biocides After having been applied on a surface a thick aqueous coating composition, it will dry out and lose water, whereby the binder forms a film that binds together the remaining ingredients of the composition and the film joins the surface to form a dry layer on the same.

A problem with the dry layers obtained at starting from thickened compositions is that the thickener residual in the layer introduces a degree of sensitivity to water, which It manifests as a "wet cleaning resistance" reduced, along with a tendency of the dry layer to soften when it gets wet, a problem that will be called "softening in wet. "For this reason, thickener concentrations in generally remain below 2% by weight of thickener not volatile per 100 g of paint composition. The problem is especially annoying if the dry layer has been obtained from a fluid coating composition in which the volume of solid particulate material is below 30% in volume (with respect to the total volume of the fluid composition of coating) and especially when the volume of binder in the Composition is below 20% by volume. This is because an amount of thickener well above 3% by weight implies giving to the coating compositions viscosities sufficiently high for practical use. The problem is further aggravated if the layer seca contains a high volume percentage of non-binding solids particulates since these dry layers are less tightly bonded and are more sensitive to water. The volume percentage of solids does not particulate binders in a dry layer is conventionally called "Pigment Content by Volume" or "PVC", even if they can other solids other than pigments are involved. The grave Water sensitivity arises in conventional dry layers if the PVC is above 70%.

Thickeners inevitably increase the water sensitivity in a dry layer because they are necessarily hydrophilic materials, as will be explained towards the end of the brief analysis of its usefulness in the compositions of following architectural cladding. A lot of thickeners and materials closely related to them, normally known as "rheology modifiers", it knows about G.D. Shay, Chapter 30 (entitled "Thickeners and Rheology Modifiers ") in his book" Paint and Coating Manual: 14th Edition of the Gardner-Sword Handbook " edited by J.V. Koleske and published in 1995 by ASTM of Philadelphia The content of this Chapter 30 is incorporated here as reference. The distinction between "thickeners" and "rheology modifiers" is somewhat arbitrary and so, with the purpose of this specification, the term "thickener" is will use to also include the "rheology modifier". Shay describes the "rheology modifiers" as "inefficient thickeners" to be used in concentrations of more than 18 g / liter (i.e. more than 1.8% by weight) when You will need a useful thickening effect.

Shay explains that the compositions of architectural coating need to have viscosities that are high enough under all effort speeds of shear, that is under high shear stresses of more than 1,000 / s, under moderate shear stresses of 10 to 1,000 / s and efforts low shear below 10 / s. In the field of architectural coatings, viscosity is measured at 18 ° C using a concentration of 2% by weight of thickener with respect to to the combined weight of water and thickener. Adequate viscosity High shear stress allows applying the compositions of brush, roller or sponge coating, with thicknesses that they allow the resulting dry layer to hide the defects on the surface and minimizing the need to apply other layers. Preferably, the high shear viscosity is 0.05 to 0.25 Pa · s when measured on a cone and plate viscometer ICI as described in ASTM Test D 4287-88, whose content is incorporated here by reference.

A suitable viscosity at a moderate speed Shear stress facilitates mixing and pumping operations during the manufacture of the coating composition and you also provides the so-called "consistency" of interest subjectively to many users. Preferably, the viscosity at Moderate speed of shear stress is 0.1 to 2.0 Pa · s measured with a Sheen Rotothinner viscometer as described in Sheen Fact Sheet called "Sheen / ICI Rotothinners" from Sheen Instruments Ltd. of Kingston on Thames, England. He Content of this Data Sheet is incorporated here as reference.

A suitable viscosity at low speed of shear stress inhibits the sedimentation of the ingredients solids when coating compositions are stored. In second, a low shear viscosity of this type reduces the risk of coating compositions liquids slide down the vertical surfaces on which They just applied. These landslides generate a disfigurement called "shift". Third, lets load large amounts of the coating composition in a tool such as a brush or roller. Preferably, the Low shear viscosity should be 20 to 150 Pa · s measured with a Brookfield viscometer as described in ASTM Test D2196 using Spindle No. 3, at a rotation speed 12 rpm The content of ASTM Test D2196 is incorporated here as reference.

Most binder formulations film-forming polymers and non-particulate solids in water they have a sufficiently high viscosity in one or more of the shear stress speed conditions exposed previously. In particular, this occurs when the composition fluid coating contains less than 30% by volume of solid materials and especially if it contains less than 20% of binder. Therefore, as Shay indicates, usually Formula viscosities increase by adding 3 at 18 g of thickener per liter of coating composition; is that is, concentrations of 0.3 to 1.8% by weight. According to Shay, the viscosity increase is usually caused by one of the three mechanisms that work alone or in combination. The three mechanisms are known as "hydrodynamic", "flocculators" and "associative". The three understand interactions involving macromolecules containing skeletons high molecular weight high molecular weight polymers greater than 30,000, preferably more than 50,000.

The viscosities at three speeds of shear stress can be conveniently measured together using a "Carri-Med" CSL 100 rheometer supplied by TA Instruments Limited of Leatherhead, England.

The hydrodynamic mechanism is the mechanism essential used by traditional macromolecular thickeners such as gums, cellulose derivatives, polyethoxylates, polyacrylamides, polyvinyl alcohols and others related by Shay in his Table 2. The mechanism requires a water sensitive macromolecular thickener comprising a high molecular weight hydrophilic skeleton devoid of any hydrophobic character. When adding the thickener to water, its hydrophilic skeleton unwinds and occupies a large hydrodynamic volume in the solution, thus immobilizing large volumes of water and generating a substantial increase in viscosity.

The flocculating mechanism is a mechanism used also for traditional thickeners that comprise skeletons high molecular weight hydrophilic and that are sensitive to water and devoid of significant hydrophobic character. In this mechanism, the hydrophilic nature of the thickener causes it to concentrate with the water in predominantly aqueous regions of the composition of coating while polymeric binder particles will they form and concentrate in predominantly hydrophobic regions. The concentrated particles of the binder touch each other and form flocs that prevent creep, thus increasing substantially the viscosity of the composition of coating.

The associative mechanism requires one more type thickener modern known as "associative thickener" as which Shay relates in Tables 4 and 5. Like the Traditional thickeners, associative thickeners are macromolecular and should raise the viscosity of water or others aqueous media either by virtue of their solubility or because they they become water soluble by a simple change in pH, for example by neutralizing the acid groups or Basic incorporated in the thickener. They must also contain a High molecular weight skeleton with a hydrophilic character. Without However, in the associative thickeners, the hydrophilic parts are adjacent to hydrophobic parts, sometimes referred to as "hydrophobic modifications". When the thickener is added associative to an aqueous coating composition, the parts hydrophilic attract large volumes of water while the hydrophobic parts are associated with analogous parts in other skeleton chains and / or are associated with hydrophobic parts of the hydrophobic particles of the composition, for example particles of binder or pigment, opacifier or extender. This association creates reversible three-dimensional physical networks in the shear effort which are bulky and trap large volumes of water, preventing thus creep and causing a substantial increase in viscosity of the coating composition.

It will be observed from the previous analysis that the presence of the hydrophilic character is essential for the mechanism whereby thickeners thicken the aqueous compositions of coating. This means that the presence of waste hydrophilic in the dry layers obtained from the thick coating compositions is inevitable, which explains why using thickeners so far is accompanied inevitably with an increase in water sensitivity of dry layers An example of the use of a type is provided particular thickener in an aqueous coating in the US 5,504.123 of Partan published in 1996. Partan reveals the use of an associative thickener comprising cellulose ether chains Water sensitive high molecular weight (10,000 to 500,000) in the which autooxidable parts have been grafted (as described later in this specification) that contain 4 to 20 carbon atoms When a coating is allowed to dry composition, the parts self-oxidize and produce a dry layer more Hard and more durable. A problem with cellulose ether chains is that its hydroxyl groups cause high viscosities in water and, unfortunately, the grafting of the autooxidant parts on the cellulose ether chains, which already have a viscosity high, produces thickeners with an even higher viscosity, so which, therefore, can only be used in casualties concentrations in the coating compositions, for example at concentrations of 0.05 to 3% by weight as proposed by Partan. Reduce the molecular weight of such cellulose ether chains to lowering viscosity increases water sensitivity, which It results in poorer characteristics. The inability to use a high concentration of cellulose ether thickeners self-oxidizing is a particular inconvenience when the layers Dried have been obtained from coating compositions fluid and containing less than 30% by volume of solids particulates and more so if dry layers also contain less of 20% by volume of binder, and so, in particular, if the layer seca has a high PVC, for example a PVC above 70%.

An object of this invention consists in provide thick aqueous coating compositions that contain a macromolecular thickener and a polymeric binder film forming, compositions that produce dry layers with less water sensitivity and that, thus, can tolerate greater thickener concentrations. Another object is to provide thick coating compositions containing low volumes of solid materials, especially binders, and that, however, they can produce dry layers with a PVC greater than 70% and with the adequate resistance to wet cleaning and softening in damp. An associated object is to provide a thickener for use in these coating compositions and a polymerizable compound for use in the manufacture of thickener Another object is to provide a thickener that may also serve, in certain circumstances, as a binder polymeric, thus avoiding the need for the composition of coating contains a separate polymeric binder.

Consequently, this invention provides a thick aqueous coating composition with a determined pH that contains a polymeric binder and a macromolecular thickener where

to)

such thickener contains macromolecules that have parts that are hydrophilic at the chosen pH, and

b)

such thickener, dispersed in water at a concentration of 2% by weight (with with respect to the thickener and water weights combined), it has a low shear viscosity of at least 0.1 Pa · s (preferably 1 to 20 Pa · s) when measured at 18 ° C in a Brookfield viscometer with a No. 3 Spindle that rotates to 12 rpm

and in which macromolecules They are cellulose free and contain auto-oxidizable parts, generating thus a cellulose-free self-thickener. The compositions they can contain more than 3% by weight (often even more than 10% in weight) of thickener and are easy to handle and produce dry layers They are not unduly sensitive to water. Of course, you can also manufacture compositions containing less than 3% by weight of thickener The coating compositions are preferably architectural siding that includes paints, lacquers, varnishes, wood stains and adhesives

The "autooxidable parts" are parts that they can react with oxygen at room temperature, usually in presence of a catalyst known as "secant", to produce bonds with other oxidizable parts in macromolecules adjacent analogues. Autooxidation is the process by which alkyd paints supported in a conventional solvent they form dry layers that have, among other things, good resistance to wet cleaning and wet softening. It has been discovered now that autoxidation can also confer resistance to wet cleaning and wet softening to the dried layers obtained according to the invention, including those that have a PVC greater than 70% and / or those obtained at from fluid coating compositions containing Only a low volume of solid particulate materials. Be explains the way in which alkyd paints oxidize in pages 156 to 160 of the book "Introduction to Paint Chemistry" of GPA Turner published in 1988 by Chapman and Hall, London. He Content of these pages is incorporated here by reference. Be You must explain that this type of oxidation is also known as "drying" although the oxidation mechanism itself does not depend on the loss of liquid by volatilization. Turner illustrates the parts self-oxidizing comprising ethylenic double bonds and the "secants" which are polyvalent metal esters, for example cobalt or manganese octoates or naphthenates and which catalyze the autoxidation reaction. Zirconium esters are also used as secants. Dryers are used at various concentrations and these can be easily determined by specialists in the matter. Typically, up to 0.2% by weight of metal is used with Regarding the complete paint composition.

Autooxidation can be accelerated by presence of easily oxidizing compounds and especially polyunsaturated compounds such as maleinized polybutadiene, where polybutadiene parts have a weight average molecular weight from 3,000 to 7,000 and where the maleic parts provide the water dispersibility Preferably, the composition of coating contains 0.1 to 1% by weight of these compounds easily oxidizing

The autooxidants parts can be obtained at from a wide variety of unsaturated materials, but those that they are most commonly used, for example in alkyd paints, derived from long chain unsaturated fatty acids containing from 12 to 30 carbon atoms. A list of these is provided fatty acids on pages 215 and 216 of Volume 1 of the book "Outlines of Paint Technology" by W.M. Morgans and published in 1982 by Griffin, London, incorporating the content of these pages here for reference. Among commercial fatty acids most important related by Morgans are fatty acids Flaxseed oil, soybean oil, oil Safflower and sunflower and long oils. These chain fatty acids long are also examples of fatty acids useful in the manufacture of the self-oxidizing thickeners of this invention. The utilization of these long chain fatty acids also has the advantage of introducing hydrophobic parts in the thickener, providing the means for its use in mechanisms associative thickeners.

A preferred technique to introduce auto-oxidizable parts involves taking a copolymerizable compound, or monomer, containing a part of unsaturated fatty acids of long chain and its copolymerization with other monomers used in thickener macromolecules production. Some of these others monomers will have parts that are hydrophilic at the pH chosen for the coating composition. In effect, copolymerization generates a macromolecule whose skeleton contains hydrophilic parts adjacent to the hydrophobic parts of the chain fatty acids Long depending on the skeleton. An outline of the reaction for this type of copolymerization in Figure 1 of the drawings. Preferably, the copolymerizable compound containing the fatty acid portion must comprise 2 to 30% by weight (and especially 4 to 15% by weight) of monomers that are copolymerize to create thickener macromolecules. Generally, the monomers containing the hydrophilic parts they must comprise 10 to 40% by weight (especially 20 to 40%) of the copolymerized monomers to create the macromolecules.

Suitable comonomers available for your use in the formation of the rest of the polymeric skeleton include alkyl esters of unsaturated carboxylic acids, by example methyl, ethyl, butyl and 2-ethylhexyl esters of Acrylic or methacrylic acids, vinyl esters such as acetate vinyl or vinyl "Versatatos" 1, α-olefins such as ethylene, propylene or 1-butene and styrene or their counterparts. Styrene copolymerized and its counterparts have the additional advantage of being particularly active in the generation and coupling to free radicals and thus promote the process of autoxidation, which in turn accelerates the initiation of water resistance.

The hydrophilic character that is essential for thickener mechanisms can be provided by comonomers containing hydrophilic parts such as hydroxyl groups or ionic groups. Examples of comonomers that can provide hydroxyl groups include hydroxyethyl acrylate or acetate vinyl after it has been subsequently hydrolyzed to basically produce a copolymerized vinyl alcohol. Others comonomers, such as carboxylic acids or their anhydrides or amides, they can introduce the hydrophilic character whenever a pH is chosen Suitable for coating composition. The choice of a pH above 7 converts carboxylic acid groups copolymerized carboxylics, or their anhydrides, in anions hydrophilic carboxylate. Again, carboxylic acid / anhydride Suitable include acrylic, methacrylic, crotonic or Itaconic or succinic anhydrides. Similarly, the choice of a pH below 7 converts the amino and amide groups of the amino / amides copolymerized in hydrophilic cations. Comonomers Suitable amino / amides include dimethylaminoethyl methacrylates or of tert-butylaminoethyl or acrylamide or methacrylamide

1 The "Versatate" of Vinyl is the vinyl ester of the so-called "Versatic" acid, which it is a mixture of aliphatic monocarboxylic acids that contain each an average of 9, 10 or 11 carbon atoms and that is commercially available from Shell Chemical Company, Carrington, England.

Sodium Acrylamidopropane Sulfonic Acid is an example of a comonomer that can be given a hydrophilic character anionic or cationic.

The copolymerizable compound containing the part of fatty acids may be a diester formed by reaction of the long chain fatty acid with the oxirane group of a monomer ethylenically unsaturated such as acrylate or methacrylate glycidyl Such a reaction produces an auto-stainless monomer copolymerizable hydroxypropylene diester comprising the part of unsaturated long chain fatty acid bound to an ester of a carboxylic acid unsaturated by the hydroxypropylene group divalent Unsaturation of the unsaturated carboxylic acid ester is then available for copolymerization with others monomers to form the skeleton of a macromolecule of thickener while unsaturation of derivatives Long chain fatty acid dependent returns to thickener stainless Preferably, the copolymerizable compound is Store at low temperature to improve the stability of storage.

As hydroxypropylene diesters are long unsaturated fatty acid reaction products chain, copolymerizable carboxylates have the advantage that of are relatively easily available, but they also have the inconvenient of having a very low water solubility, which inhibits its activity in aqueous copolymerization processes conventional, except, appearing some unsuitable amounts from the environmental point of view of organic cosolvents. It has been discovered that this problem can be solved by agitation of the comonomers (including the copolymerizable compound such as diester) together with water, the polymerization initiator and the agent surfactant and then by subjecting the stirred mixture to a intensive agitation to create a very large number of drops very small (less than 500 nm in diameter) of comonomer. The initiator polymerization can be water soluble or oil soluble; that say soluble in the monomers. When using an initiator oil soluble, for example lauroyl peroxide, it is preferred that dissolve first in the monomers and stir intensive before causing polymerization to continue. When uses a water soluble polymerization initiator, for example ammonium persulfate, this can be added before or after intensive agitation When using a water soluble initiator of this type, the copolymerization begins in the aqueous phase, but then the copolymerizing system will migrate to the organic zones created by the drops in which the copolymerization will continue. The migration will be fast because it is favored by the large area surface provided by the large number of tiny drops of comonomer This migration allows the effective copolymerization of monomers of very low water solubility, in this case the copolymerizable self-oxidizing compounds.

A preferred diester comprises parts methacrylate and parts derived from fatty acids from oils long

The polymerization can be carried out by raising the temperature. Preferably temperatures of 30 to 98 ° C are used. Additionally and as an alternative, a system can be used redox initiator Suitable examples of these systems include hydrogen peroxide and ascorbic acid, ammonium persulfate and sodium metabisulfite or sodium sulfoxilate formaldehyde. Optionally, metal salts can be added as copper salts or iron

The necessary intensive agitation can provided by mechanical emulsifiers such as Ross 100 (of Ross and Son, Hauppauge, New York, USA) or Silverson (from Silverson Machines Ltd. Chesham, Buckinghamshire, UK) or an IKA emulsifier (from IKA-Works Inc., Cincinnati, Ohio, USA). How Alternatively, a Sonolator (from Sonic Corp., Stratford, Connecticut, USA), which uses ultrasound to generate the necessary shear effort. Preferably, the stirring is energetic enough to produce particles any thickener that, in a non-neutralized state, has average particle size below 500 nm and preferably per below 300 nm.

A more hydrophilic diester would have both advantages of being capable of purely emulsion copolymerization aqueous without the need for any intensive agitation and greater efficiency as a thickener. One way to increase solubility in water from water insoluble diesters consists of introducing the hydrophilic character in otherwise hydrophobic lateral groups of the polymeric skeleton. This can be conveniently done. linking fatty acid derivatives to unsaturated carboxylate by means of a polyethoxylate or a divalent polyether radical similar instead of the divalent hydroxypropylene group previously used

Other alternative techniques to obtain Useful copolymerizable diesters involve alcoholysis followed by an esterification or transesterification. Preferred techniques comprise the alcoholysis of an unsaturated triglyceride with a polyol, usually a diol. The alcoholysis converts the triglyceride in one of mono- or di-glycerides that They contain respectively one or two hydroxyls, while as minimum part of the polyol becomes an ester that contains the less a hydroxyl. These hydroxyls provide the means to bind esters to copolymerizable monomers with others comonomers that are copolymerized to produce the macromolecule of the thickener Preferred triglycerides are the oils used as a source of long chain unsaturated fatty acids mentioned previously, especially flaxseed oil, seed oil soybean, safflower seed oil, sunflower seed oil or long oils. Preferred diols are 1,3-butenediol and neopentyl glycol.

The hydroxyl-containing ethers above they can bind to the copolymerizable monomers to form a diester by co-reaction with the carboxylic acid groups, the carboxylic or oxirane anhydride groups associated with the monomer or by transesterification. Co-reagents Preferred are anhydrides and particularly anhydride methacrylic The transesterification is preferably performed by alkyl (C 1-8) acid esters unsaturated carboxylic acids, for example methyl, ethyl, butyl or ethoxyhexyl esters of acrylic, methacrylic, crotonic or Itaconic Both the co-reaction and the transesterification produce unsaturated diesters useful in the manufacture of thickener macromolecules. However, you can need to use the technique of intense agitation if diesters They are not very soluble in water.

In the field of thickener macromolecules, the skeleton of the macromolecule is generally considered to be the longest chain of carbon atoms and it also contains optionally oxygen and / or nitrogen atoms, which exist in the macromolecule excluding any hydrophobic side chain primary. Examples of typical polymeric skeletons are shown in Figures 2 to 4 of the drawings. Other parts, such as parts hydrophobic, hydrophilic and especially self-oxidizing, can depend on the skeleton. The skeleton must have a molecular weight average of at least 35,000, preferably at least 50,000 and usually from 10 5 to 10 6.

In addition to increasing the viscosity of the coating composition and decrease water sensitivity of the dry layers, the thickener can also self-oxidize to form a binder film and so, if enough are present self-oxidizing parts, the thickener can serve as a single binder. The amount of autooxidability needed will depend on the PVC of the Composition, higher PVCs need more autooxidability, especially when PVC exceeds 70%.

This invention also provides a aqueous dispersion of thickener with a pH chosen for use in the coating compositions where

to)

he thickener contains macromolecules that have parts that hydrophilic at the chosen pH and

b)

he thickener dispersed in water at a concentration of 2% by weight (with with respect to the thickener and water weights combined) it has a low shear viscosity of at least 0.1 Pa · s measured at 18 ° C on a Brookfield viscometer with a No. 3 Spindle that rotates at 12 rpm

in which the macromolecules are cellulose-free and also contain auto-oxidizable parts, creating thus a self-thickener free of cellulose.

This invention further provides a compound. self-curing copolymerizable for use in manufacturing of a thickener according to this invention in which the compound is a diester containing a hydroxypropylene group divalent or a divalent polyoxyethylene group and parts that are esters of acrylic and / or methacrylic acid and a part of fatty acid unsaturated long chain.

Procedure to Evaluate Cleaning Resistance in Damp

Wet Cleaning Resistance of a Dry coat of paint is evaluated as follows:

The surface of a board is painted with a commercial paint in high PVC acrylic vinyl emulsion (Dulux® Supermatt), by spray application, with a dispersion coefficient of approximately 10 square meters per liter, and allowed to dry at room temperature (15 to 20 ° C) for 48 hours. The painted surface is then painted again with a Brush using the thick aqueous paint to be evaluated. The repainted surface is allowed to dry at room temperature for one hour and then different samples of said surface are stored repainted at room temperature for periods of one, two, three and four weeks respectively.

After storage, each sample is clean 20 times with a damp cloth and evaluate the amount of visually removed paint and assigned a value according to the following scale:

one

= very poor, paint removed with 1 - 5 cleanings

3

= quite poor, which gives a soapy feeling at 10 cleanings,                      A lot of paint on the rag.

5

= poor, which gives a soapy feeling at 18 - 20 cleanings

7

= little paint removed, does not give any soapy sensation.

10

= No paint removed.

The invention is further illustrated by the Following Examples, of which Examples A to C are comparatives

Example one

Process for the production of a copolymerizable monomer Cellulose free auto-stainless

500 g of acid were charged under nitrogen long oil fat (TOFA), 8.0 g of bromide cetyltrimethylammonium and 0.7 g of hydroquinone in a bottom flask round one liter equipped with reflux condenser and stirrer. He flask content was stirred and heated to 80 ° C and then added gradually 355.0 g of glycidyl methacrylate over a period 3 hours while maintaining the temperature of 80ºC and the agitation. The temperature of 80 ° C and stirring were maintained. for 9 more hours.

During the process, the TOFA reacted with parts glycidyl methacrylate oxirane to form a diester copolymerizable where the unsaturated methacrylate parts were linked to an auto-stainless TOFA carboxylate by a group divalent hydroxypropylene. The reaction was catalyzed by bromide. of cetyltrimethylammonium and premature polymerization was inhibited with hydroquinone The resulting monomer was stored in a refrigerator at approximately 4 ° C before use. Excess is used glycidyl methacrylate molar above TOFA.

Example 2

Alternative process to Example 1

The procedure of Example 1 was repeated except that the catalyst was 11.3 g of tetraethylammonium bromide, Glycidyl methacrylate was added over a period of time. two hours and at the temperature of 80 ° C and stirring is They kept for 3 more hours instead of 9.

As in Example 1, the TOFA reaction and Glycidyl methacrylate formed a copolymerizable diester. He resulting monomer was stored in a refrigerator at approximately 4 ° C before use.

Example 3

Cellulose free copolymerizable alternative monomer stainless steel with greater hydrophilicity

40.0 g of one long oil hydroxypolyethoxy carboxylate (in this case Long liquid oil fatty acid ethoxylate with 6 units of ethylene oxide) and 2.0 g of hydroquinone in a bottom flask round one liter equipped with a reflux condenser and a agitator. The polyethoxy part contained an average number of 6 units of ethoxy. The contents of the flask were stirred and heated to 100 ° C and then 15.0 g of methacrylic anhydride were added over a period of one hour. The temperature of 100 ° C and stirring were maintained. for 3 more hours.

During the process, the hydroxypolyethoxy part esterified methacrylic anhydride to form a diester copolymerizable where the unsaturated methacrylate parts bound to the long oil carboxylate by a polyethoxy group divalent The presence of the polyethoxy bond conferred a increased hydrophilicity in the diester compared to the hydrophilicity of the auto-stainless monomer produced in Examples 1 or 2.

Example 4

Process for the production of a cellulose free thickener stainless steel to be called "Thickener Ex. 4"

The following were mixed together comonomers and hexanol in a glass beaker with temperature peak ambient:

Acrylate ethyl 165.00 g Acid methacrylic 94.00 g Methacrylate methyl 5.60 g Copolymerizable monomer of Example 1 23.50 g Hexanol 1.35 g

The mixture was slowly added, stirring, to a 2.00 g solution of sulphosuccinate surfactant dioctyl sodium (SDSS) in 386.00 g of water. The new one mixture thus obtained was subjected to intensive stirring for 10 minutes using a Silverson mixer that turned large speed, after which an emulsion comprising very fine drops of organic monomers.

The emulsion was gradually pumped for 3 hours in a solution of 0.10 g of SDSS surfactant and 2.50 g of the polymerization initiator ammonium persulfate in 808.20 g of water, kept at 80 ° C, under nitrogen, in a bottom flask round connected to a reflux condenser and a stirrer. The copolymerization started and the temperature of 80 ° C as well as the stirring was maintained for 30 more minutes after the pumping completion Then, a second solution was added comprising 0.27 g of ammonium persulfate in 2.20 g of water followed by a second period of 30 minutes at 80 ° C, with stirring. Finally, a solution of 0.18 g of formaldehyde was added sodium sulfoxylate in 2.00 g of water followed by a final period 30 minutes at 80 ° C, with stirring. The content of the flask and a particulate macromolecular thickener latex was obtained in which the particles had an average particle size of 314 nm.

The macromolecules contained a skeleton compound of copolymerized acrylate, methacrylate and acid parts methacrylic acid parts that confer a hydrophilic character to macromolecules when they experience a change in pH up to above 7. Hydrophobic parts comprising the carboxylate long oil depend on the skeleton to which they are connected by a divalent hydroxypropylene group. The parts hydrophilic and its adjacent hydrophobic parts allow the macromolecules act as associative thickener when they meet in solutions at a pH above 7 and preferably between 9 and 9.5.

Example 5

Associative thickener free of auto-stainless cellulose that                          contains styrene as Promoter of autooxidation, which will be called "Thickener Ex. 5"

The process of Example 4 was repeated but with the following modifications:

one.

comonomer mixture was what follow:

Ethyl acrylate 165.00 g Methacrylic acid 92.00 g Methyl methacrylate 6.20 g Styrene 15.00 g Copolymerizable monomer of the Example one 26.00 g

2.

The surfactant solution contained 5.00 g of SDS in 386.70 g of water.

3.

The initiator solution in the round bottom flask consisted of 0.10 g of SDSS and 2.50 of ammonium persulfate in 808.00 g of Water.

Four.

The Additional initiator solution consisted of 0.27 g of persulfate of ammonia in 2.16 g of water.

5.

The formaldehyde derivative solution was composed of 0.18 g of formaldehyde sulfoxylate sodium in 2.07 g of water.

The particle size of the dispersion was 220 nm

The autooxidable macromolecules could act as associative thickeners when they were in a solution to a pH above 7 and preferably between 9 and 9.5.

Example 5A

Associative cellulose-free alternative thickener                              stainless steel containing styrene as autoxidation promoter, which It will be called "Thickener Ex. 5A"

The process of Example 5 was repeated except that the copolymerizable monomer of Example 1 was replaced by the copolymerizable monomer of Example 2.

The autooxidable macromolecules could act as associative thickeners when they were in a solution to a pH above 7 and preferably between 9 and 9.5.

Example 6

Associative cellulose-free alternative thickener with a                        Increased hydrophilicity, which will be called "Thickener Ex. 6"

The process of Example 4 was repeated but with the following modification:

The mixture of comonomers and hexanol was like follow:

Acrylate ethyl 68.00 g Acid methacrylic 23.50 g Monomer copolymerizable from Example 3 10.00 g Hexanol 0.40 g

The thickener particles had a size 193 nm particle medium and included copolymeric macromolecules self-oxidizing Hydrophobic carboxylates of long oils (the copolymerizable monomer of Example 3) were attached to the skeleton through a divalent polyethoxy group that converted the macromolecules in more water soluble by increasing the pH to above 7. Macromolecules could act as thickeners associative in solutions at a pH above 7.

Comparative Example D

Associative cellulose-free thickener without auto-stainless group, to be called "Thickener Ex. D"

The process of Example 4 was repeated but with the following modification:

The mixture of comonomers and hexanol was like follow:

Acrylate ethyl 203.00 g Acid methacrylic 101.70 g Styrene 15.00 g Stearyl Methacrylate 33.90 g Hexanol 1.35 g

The thickener particles had a size 191 nm particle medium. The macromolecules could act as non-autooxidative associative thickeners in pH solutions above 7.

Examples 7 to 10 and Examples Comparisons A to D

Resistance to wet cleaning of the dry layers obtained from thick aqueous paints

In Examples 7 to 10, aqueous paints thickeners were manufactured using associative thickeners self-oxidizing, as provided by this invention, and from conventional ingredients all of them, as specified in Tables 1 and 2. Similarly, thick aqueous paints were prepared in Comparative Examples A to D unless they used the associative thickeners Commercial non-self-oxidizing Examples Comparatives A to C and the "Thickener Ex. D" was used in the Comparative Example D. Again, the ingredients and quantities employees are specified in Tables 1 and 2.

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Each paint was manufactured using the following procedure The dispersant, the biocide, the solvent coalescing and the antifoaming agent all dissolved in a 50% water share. Plaster, clay and rutile were added to the solution, which was then subjected to high speed dispersion in a "Dispermat" mixer that worked at 400 rpm. While both the latex binder and any cobalt accelerator and secant necessary were being stirred in the other part of 50% water. He thickener and ammonia were then stirred in this other part of water and both parts of water were stirred together to Produce the final paint formulation. The surface was of previously painted plasterboard with Dulux Supermatt and aged for a week before being coated with test paints Each test paint was applied to a surface and allowed to dry for one hour at room temperature to produce a dry layer. The dried layers were then stored at room temperature for periods of 1, 2, 3 and 4 weeks and, after having stored a layer during one of these periods, its wet cleaning resistance was evaluated using the procedure described earlier in this specification.

Valuations and periods after which are made are shown in Table 3 together with the PVC of the dry layers and the amount (in parts by weight) of thickener used in aqueous paint (i.e. before the paint it will start to dry).

Table 3 demonstrates that the use of self-oxidizing thickeners substantially increases the resistance to Wet Cleaning of dry layers, even when the PVC of the Dry layers exceed 70% and even when the amount of thickener used exceeds that used for associative thickeners conventional non-autooxidables, in a factor of at minus 3 and sometimes higher than 5. This ability to use much larger amounts of thickener allows the thick aqueous coating compositions are made when the thickener is self-stainless as illustrated by the viscosities shown in Table 4. Examples 7 and 8 of the Table 3 demonstrate the advantages of incorporating styrene into the thickener macromolecular A pre-storage inspection preliminary indicated that the autoxidation of the paint of Example 10 It was slow due to the absence of unsaturated accelerator.

TABLE 1 Ingredients of the Formulations of Painting

Ingredients Examples: parts by weight 7 8 9 10 TO B C D Dispersant 0.30 0.30 0.10 0.30 0.50 0.30 0.30 0.30 Biocide 0.20 0.50 0.01 0.20 0.50 0.50 0.20 0.20 Solvent coascent 0.70 0.50 4.00 0.40 0.40 0.50 0.70 0.50 Agent antifoam 0.30 0.20 0.04 0.10 0.20 0.20 0.30 0.20 Water 51.01 37.50 43.29 42.59 46.30 44.00 55.10 45.69 Cast 12.60 21.20 26.00 19.20 20.60 21.60 12.90 19.20 Kaolin 14.00 14.80 -  \ hskip0.2cm 16.30 14.40 15.00 14.00 16.30 Rutile 7.40 6.10 6.40 6.00 6.00 6.30 7.40 6.00 Latex binder 5.30 5.70 -  \ hskip0.2cm 3.60 9.70 10.20 7.00 5.20 Throttle 0.39 0.99 0.88 -  \ hskip0.2cm - \ hskip0.2cm -  \ hskip0.2cm -  \ hskip0.2cm 0.50 Dryer cobalt 0.01 0.01 0.02 0.01 -  \ hskip0.2cm - \ hskip0.2cm -  \ hskip0.2cm 0.01 Thickener Ex. 4 7.60 - \ hskip0.2cm -  \ hskip0.2cm 11.00 -  \ hskip0.2cm - \ hskip0.2cm -  \ hskip0.2cm -  \ hskip0.2cm Thickener Ex. 5A -  \ hskip0.2cm 11.90 -  \ hskip0.2cm - \ hskip0.2cm -  \ hskip0.2cm - \ hskip0.2cm -  \ hskip0.2cm -  \ hskip0.2cm Thickener Ex. 5 -  \ hskip0.2cm -  \ hskip0.2cm 19.00 -  \ hskip0.2cm - \ hskip0.2cm -  \ hskip0.2cm - \ hskip0.2cm -  \ hskip0.2cm Thickener conventional - \ hskip0.2cm -  \ hskip0.2cm - \ hskip0.2cm -  \ hskip0.2cm 1.10 1.10 1.90 -  \ hskip0.2cm Thickener Ex. D -  \ hskip0.2cm - \ hskip0.2cm -  \ hskip0.2cm 0.30 -  \ hskip0.2cm - \ hskip0.2cm -  \ hskip0.2cm 5.60 Solution ammoniacal (33-35%) 0.20 0.30 0.26 0.30 0.30 0.20 0.28 Total 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00

The viscosities increase and decrease the shear stress coefficients were measured with a rheometer Cari-Med CSL 100. The measurements were made increasing the shear stress coefficient (above) and then after a 2 minute break, decreasing the coefficient of shear stress (below). The differences in viscosities measures by increasing and decreasing viscosities at a coefficient of Shear stress indicate a thixotropy. Were all thixotropic

TABLE 2 Ingredients Detail

Ingredient Details Dispersant "Calgon": Ellis Everard Ltd. of Bradford, UK. Biocide V 189: KMZ Chemicals Ltd. of Cobham, UK. Solvent coascent "Texanol": Eastman Chemicals (UK) Ltd. of Liverpool, UK Agent antifoam "Foamaster" G: Henkel of Madison Heights, MI, USA Latex binder  \ begin {minipage} [t] {120mm} "Emultex" 4057: acrylic / vinyl latex from Revertex Chemicals Ltd. of Hartlepool, UK. \ End {minipage} Throttle  \ begin {minipage} [t] {120mm} "Lithene": 25% maleinized polybutadiene by weight, weight molecular 5,000, from Revertex Chemicals Ltd. of Hartlepool, UK. \ End {minipage} Thickener conventional  \ begin {minipage} [t] {120mm} "Acrysol" DR1 - associative thickener: Rohm and Haas (UK) Ltd. of Croydon, UK. \ End {minipage} Thickener Ex. D Thickener of Comparative Example D including styrene copolymerized DER 333 Diepoxy Resin Dow Chemical Canada Sarma Ontario Canada N7T 7K7

The unexpected advantage is that the quantities Increased auto-thickener produced resistance to Wet cleaning increased while increasing Conventional thickener would decrease the Cleaning Resistance by Damp. This advantage is supposed to be possible because the increase in self-oxidization leads to an increase in resistance to Wet cleaning that compensates for the expected decrease of an increased amount of hydrophilic parts.

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TABLE 3 Humidity Cleaning Resistance Assessment with a scale from 1 (poor) to 10 (good)

Period after which Example and assessment made the assessment 7 8 9 10 TO B C D After 1 week 6 5 9 3 one 2 4 2 After of 2 weeks 6 7 9 4 2 2 4 3 After of 3 weeks 7 8 9 5 3 3 5 - After of 4 weeks 8 9 9 6 3 3 5 - PVC Layer Dry 74 72 76 77 73 73 74 77 * Parts by weight of the solution 7.6 11.9 19 11.2 1.1 1.1 1.9 5.6 from thickener in the painting (1.5) (2.5) (3.8) (2.5) (0.3) (0.3) (0.6) (1,2) * \ begin {minipage} [t] {150mm} The numbers between parentheses refer to the weight of dry thickener per 100 g of wet paint composition \ end {minipage}

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TABLE 4 Viscosities of the paintings thickened

Coefficient of Shear stress Examples: Viscosity in Pa. Sec. up and then down 7 TO B * Low 172 69 129 * Means, medium 2.32 1.95 3.7 * Tall 0.21 0.21 0.27 ** Tall 0.21 0.17 0.27 ** Means, medium 2.1 1.5 3.2 ** Low 106 49 98 * Upwards ** Towards Down  \ begin {minipage} [t] {150mm} Shear stress low = 0.1 / s; average shear stress = 40 / s; shear effort high = 1,000 / s \ end {minipage}

Examples 11 to 13

Alternative method to provide a thickener free of auto-stainless cellulose by esterification and transesterification

First a mixture of hydroxy was made self-oxidizable esters by alcoholysis of seed oil soybean (Example 11), safflower seed oil (Example 12) or flaxseed oil (Example 13). The alcoholysis was carried out with 1,3-butenediol.

To make the esters, they were loaded, under nitrogen, 300.0 g of one of the oils in a bottom flask round connected to a reflux condenser. 1.5 g of lithium neodecanoate and the flask and its contents were heated to 200 ° C for 1 hour. 61.5 g of 1,3-butenediol for 5 minutes, followed by heating at 240 ° C for 45 minutes. A mixture of hydroxy unsaturated esters autooxidables.

300.0 g of the ester mixture was added previously obtained at 174.0 g of methacrylic anhydride content in a round bottom flask connected to a reflux condenser. 0.1 g of hydroquinone methyl ether (MEHQ) was added as an inhibitor polymerization and the mixture was heated at 100 ° C for 3 hours. Be obtained an auto-stainless mixture of monomers comprising parts of methacrylate and long chain unsaturated parts derived from oil.

The self-mixing monomer mixture became in a self-associative thickener as follows. A mixture containing the self-mixing monomer mixture and what next:

Auto Stainless Mix monomers from above 30.0 g Methacrylic acid 44.0 g Ethyl acrylate 76.0 g Sodium C14 sulfonate a C_ {18} 3.0 g Water 200.0 g

The mixture was emulsified by subjecting it for 15 minutes to intense agitation provided by a Ross Emulsifier ME-100 at 10,000 rpm. 30.0 g of the emulsion obtained at 288.0 g of water that had been heated previously at 80 ° C, under nitrogen. Then the reagents and water at 80 ° C until final cooling. They were added 0.8 g of ammonium persulfate in 16.0 g of water to the emulsion in the water previously heated and allowed to stand for 30 minutes The rest of the emulsion was added gradually over 2 hours and let everything rest again for 30 minutes. Be they added 0.2 g t-butyl hydroperoxide followed by  another 30 minutes of rest. Then 0.14 g of sodium sulfoxylate formaldehyde in 2.0 g of water followed by a 30 minute rest. The last two additions were repeated and rest and then let everything cool to room temperature. Be obtained a stainless steel thickener that could be used to thicken and flirt the paint.

Example 14

Use of transesterification

The following mixture was made:

Auto stainless monomer Example 13 160.0 g Acrylate ethyl 160.0 g DER 333 (epoxy resin Dow liquid) 3.0 g Dibutylamine 1.5 g MEHQ inhibitor 0.1 g

The mixture was loaded in a round bottom flask connected to a glass filler column and heated to 125 ° C for a period of 2.5 hours while ensuring that the temperature at the top of the column was maintained by below 80 ° C. This caused the transesterification after which a flask was collected from the flask 20 ml distillate that included the auto-stainless monomer.

The auto-stainless monomer was used to manufacture a stainless steel thickener according to the procedure from Examples 11 to 13 but with the following changes:

one.

Be they used 7.5 g of the auto-stainless monomer,

2.

Be they used 7.5 g of methacrylic acid, and

3.

Be they used 40.0 g of ethyl acrylate.

This thickener can be used in paint formulations as described above.

This invention is further illustrated by the figures. where

Figure 1: shows a reaction scheme for introduce the lateral hydrophobic parts into a skeleton polymeric

Figure 2: shows a polymeric skeleton that It contains only carbon atoms.

Figure 3: shows a polymeric skeleton that It contains both carbon and oxygen atoms.

Figure 4: shows a polymeric skeleton that It contains carbon, oxygen and nitrogen atoms.

Figure 1 shows a reaction scheme for the copolymerization of a long oil methacrylate that contains the part of long liquid oil with other comonomers ethylenically unsaturated to form a skeleton that leads from that hang oil side auto-oxidizable hydrophobic parts long.

Figure 2 shows an all carbon skeleton which contains 6 + 2n carbon atoms as it could be obtained from the polymerization initiated via free radicals and subsequent hydrolysis of vinyl acetate to basically produce an alcohol of polyvinyl. The groups whose terminals in the chain are shown arbitrarily as hydrogen atoms. Hydrophobic parts laterals could be attached to the skeleton by condensation with hydroxyl groups.

Figure 3 shows a carbon skeleton and oxygen that contains 6 + 2n carbon atoms and 2 + n oxygen atoms. Again, hydroxyl groups could be used for the binding of hydrophobic groups.

Figure 4 shows a skeleton comprising carbon, oxygen and nitrogen atoms as found in the ethoxylate urethanes.

Claims (17)

1. Aqueous thick coating composition with a given pH containing a polymeric binder and a macromolecular thickener where

to)

such thickener contains macromolecules that have hydrophilic parts at pH chosen, and

b)

such thickener dispersed in water at a concentration of 2% by weight (with with respect to the thickener and water weights combined) it has a low shear viscosity of at least 0.1 Pa · s when measured at 18 ° C on a Brookfield viscometer with a No. 3 Spindle which rotates at 12 rpm

characterized in that the macromolecules are cellulose free and because they also contain auto-oxidizable parts, thus creating a cellulose-free auto-thickener. 2. Composition according to claim 1, characterized in that the composition contains a secant that catalyzes the autooxidation of the autooxidable parts. 3. Composition according to claim 1 or claim 2, characterized in that the auto-oxidizable parts are provided by long-chain unsaturated fatty acids. 4. Composition according to any one of claims 1 to 3, characterized in that the auto-oxidizable parts are provided by a copolymerized diester comprising a divalent hydroxypropylene group. 5. Composition according to any one of claims 1 to 3, characterized in that the auto-oxidizable parts are provided by a copolymerized diester comprising a divalent polyether radical. 6. Composition according to any one of claims 1 to 5, characterized in that the macromolecules contain copolymerized styrene or a styrene analog. 7. Composition according to any one of claims 1 to 6, characterized in that the composition contains a polyunsaturated compound. 8. Composition according to claim 7, characterized in that the polyunsaturated compound contains polybutadiene parts. 9. Composition according to any of the preceding claims, characterized in that the composition contains more than 3% by weight (with respect to the total weight of the composition) of the thickener. 10. Composition according to any one of claims 1 to 8, characterized in that the composition contains up to 3% by weight (with respect to the total weight of the composition) of the thickener. Composition according to any one of claims 1 to 10, characterized in that the composition contains less than 30% by volume of solid material. 12. Process for manufacturing a coating composition according to any one of claims 1 to 11, characterized in that the thickener is made by intensively agitating the comonomers from which the polymeric skeleton is obtained. 13. Paint, lacquer, varnish, wood stain or architectural adhesive comprising a composition of coating according to any one of claims 1 to 11 or manufactured according to claim 12 and containing more than 3% in thickener weight 14. Thick aqueous dispersion at a given pH for use in coating compositions where

to)

such thickener contains macromolecules that have parts that are hydrophilic at the chosen pH and

b)

such thickener dispersed in water at a concentration of 2% by weight (with with respect to the thickener and water weights combined) it has a low shear viscosity of at least 0.1 Pa · s when measured at 18 ° C on a Brookfield viscometer with a No. 3 Spindle which rotates at 12 rpm,

characterized in that the macromolecules are cellulose free and also contain auto-oxidizable parts, thus creating a cellulose-free auto-thickener. 15. Dispersion according to claim 15, characterized in that in the non-neutralized state, the thickener particles have an average particle size below 500 nm.

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16. Composition according to any one of claims 1 to 11 or 13, characterized in that the polymeric binder and the cellulose-free macromolecular thickener comprise the same material. 17. Composition according to any one of claims 1 to 11 or 13, characterized in that the dry layer obtained from said composition has a PVC of at least 70%.